NEW YORK (Reuters) - The chief executive of Roche Holding AG said on Wednesday the Swiss drugmaker’s experimental drugs to treat melanoma and raise “good” HDL cholesterol could transform treatment of cancer and heart disease.

In an interview, Roche Chief Executive Officer Severin Schwan said its drug designed to raise good cholesterol, called dalcetrapib, “could be a game changer in how we treat lipid diseases,” noting it is being tested in 15,000 patients in partnership with Japan Tobacco Inc.

“You can imagine if it proves to be positive this will change medicine,” Schwan said. “We’re talking about a very big drug.”

Schwan said the company plans to seek approval in 2013 for the product.

Schwan spoke to Reuters in New York a day before the drugmaker holds its first review of its pipeline for analysts and investors since its purchase of Genentech a year ago.

The CEO also expressed high hopes for an experimental melanoma drug, R7204, which has been advanced into late-stage testing.

“The drug has reduced tumor size by 70 percent and some patients are in full remission,” Schwan said. “The life of patients has been prolonged.”

The drug has also “made a huge difference in quality of life” by ending bone pain for some patients, he said.

If late-stage trials confirm what has been seen so far, Schwan said, “this will change the treatment of metastatic melanoma.”

Schwan said the drug has shown highly promising results among patients that have a mutated form of a protein called BRAF, presumably because the altered protein greatly accelerates cell growth -- a hallmark of cancer.

Roche has developed a diagnostic product that can identify which patients have the mutated protein and are therefore most likely to benefit from R7204 -- its companion drug.

“(R7204) could become the poster child of personalized medicine,” Schwan said, referring to its ability to be targeted to specific patients thanks to a diagnostic product.

Some analysts have said R7204 has potential to capture annual sales of about $800 million, a bit shy of blockbuster status.

Schwan acknowledged there is “a rather small population” of patients with metastatic melanoma, but said R7204 also has a good chance of being able to treat colon cancer and other types of cancer that are likewise linked to the mutated BRAF protein.

“If we can take out other cancer types, this could be a very big drug,” Schwan said.

Many analysts attending Roche’s planned meeting on Thursday will want reassurance of strong continued growth prospects for the company’s three flagship products -- Herceptin for breast cancer, Rituxan (Mabthera) for non-Hodgkin’s lymphoma and Avastin for colon cancer and other tumors.

“We see good growth potential” for them, Schwan said, even though the trio have already been mainstay treatments for years.

Herceptin’s growth should come, in part, from overseas use of the medicine for stomach cancer, he said, while Avastin will be helped by recent approval to treat ovarian cancer.

Schwan said he could not comment on whether Roche would be interested in making a rival bid for OSI Pharmaceuticals Inc, Roche’s partner on the cancer drug Tarceva.

OSI’s board has rejected a $3.5 billion takeover bid by Japan’s Astellas Pharma Inc and analysts have said Roche could be a potential rival buyer because of the Tarceva partnership.